Yeast‐Raised Polyamidoxime Hydrogel Prepared by Ice Crystal Dispersion for Efficient Uranium Extraction from Seawater

Abstract Uranium extraction from seawater has attracted worldwide attention due to the massive reserves of uranium. Due to the straightforward synthesis and strong affinity toward uranyl ions (UO2 2+), the amidoxime group shows promise for use in highly efficient uranium capture. However, the low mass transfer efficiency within traditional amidoxime‐based adsorbents severely limits the adsorption rate and the utilization of adsorption sites. In this work, a macroporous polyamidoxime (PAO) hydrogel is prepared by yeast‐based biological foaming combined with ice crystal dispersion that effectively maintained the yeast activity. The yeast‐raised PAO (Y‐PAO) adsorbent has numerous bubble‐like holes with an average pore diameter >100 µm. These macropores connected with the intrinsic micropores of PAO to construct efficient diffusion channels for UO2 2+ provided fast mass transporting channels, leading to the sufficient exposure of hidden binding sites. The maximum adsorption capacity of Y‐PAO membrane reached 10.07 mg‐U/g‐ads, ≈1.54 times higher than that of the control sample. It took only eight days for Y‐PAO to reach the saturation adsorption capacity of the control PAO (6.47 mg‐U/g‐ads, 28 days). Meanwhile, Y‐PAO possessed excellent ion selectivity, good reusability, and low cost. Overall, the Y‐PAO membrane is a highly promising adsorbent for use in industrial‐scale uranium extraction from seawater.


Table of Contents
Figure S9 | SEM images of Y-PAO membranes with different volume ratio of PAO and yeast.
Table S1 | Fitting parameters of adsorption kinetics data based on pseudo-second-order and pseudo-first-order models.

Figure S14 |
Figure S14 | High-resolution XPS spectra of O 1s for Y-PAO before and after uranium

Figure S8 .
Figure S8.Volume changes for PAO and Y-PAO membranes before and after alkali treatment.

Figure S9 .
Figure S9.SEM images of Y-PAO membranes with different solution volume ratio of PAO and yeast.

Figure S17 .
Figure S17.Digital photographs of Y-PAO membranes before and after uranium adsorption in nature seawater. .

Table S2 |
Uranium adsorption capacities of PAO and Y-PAO membranes at different times.19

Table S3 |
Fitting parameters of equilibrium adsorption isotherms of Y-PAO based on Langmuir and Freundlich models.

Table S6 |
Concentration of uranium and competitive metal ions in natural seawater and metalion-spiked seawater.

Table S1 .
Fitting parameters of adsorption kinetics data based on pseudo-second-order and pseudo-first-order models.

Table S2 .
Uranium adsorption capacities of PAO and Y-PAO membranes at different times.

Table S3 .
Fitting parameters of equilibrium adsorption isotherms of Y-PAO based on Langmuir and Freundlich models.

Table S4 .
Uranium adsorption capacity of Y-PAO adsorbent at different cycle numbers in natural seawater.The adsorption capacity is estimated based on 5-cycle reusability test of Y-PAO in U-spiked simulated seawater.

Table S5 .
Economic cost of industrial raw materials for 1 kg uranium production.

Table S6 .
Concentration of uranium and competitive metal ions in natural seawater and metal-ion-spiked seawater.